Risk factors of postoperative delirium following spine surgery: A meta-analysis of 50 cohort studies with 1.1 million participants.

Objectives: Postoperative delirium (POD) is considered to be a common complication of spine surgery. Although many studies have reported the risk factors associated with POD, the results remain unclear. Therefore, we performed a meta-analysis to identify risk factors for POD among patients following spinal surgery. Methods: We systematically searched the PubMed, Embase and the Cochrane Library for relevant articles published from 2006 to February 1, 2023 that reported risk factors associated with the incidence of POD among patients undergoing spinal surgery. The Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed, and random effects models were used to estimate pooled odds ratio (OR) estimates with 95 % confidence intervals (CIs) for each factor. The evidence from observational studies was classified according to Egger's P value, total sample size, and heterogeneity between studies. Results: Of 11,329 citations screened, 50 cohort studies involving 1,182,719 participants met the inclusion criteria. High-quality evidence indicated that POD was associated with hypertension, diabetes mellitus, cardiovascular disease, pulmonary disease, older age (>65 years), patients experiencing substance use disorder (take drug ≥1 month), cerebrovascular disease, kidney disease, neurological disorder, parkinsonism, cervical surgery, surgical site infection, postoperative fever, postoperative urinary tract infection, and admission to the intensive care unit (ICU). Moderate-quality evidence indicated that POD was associated with depression, American Society of Anesthesiologists (ASA) fitness grade (>II), blood transfusion, abnormal potassium, electrolyte disorder, length of stay, inability to ambulate and intravenous fluid volume. Conclusions: Conspicuous risk factors for POD were mainly patient- and surgery-related. These findings help clinicians identify high-risk patients with POD following spinal surgery and recognize the importance of early intervention.

Risk factors of epidural hematoma in patients undergoing spinal surgery: a meta-analysis of 29 cohort studies.

OBJECTIVE: The authors conducted this meta-analysis to identify risk factors for spinal epidural haematoma (SEH) among patients following spinal surgery. METHODS: The authors systematically searched Pub: Med, Embase, and the Cochrane Library for articles that reported risk factors associated with the development of SEH in patients undergoing spinal surgery from inception to 2 July 2022. The pooled odds ratio (OR) was estimated using a random-effects model for each investigated factor. The evidence of observational studies was classified as high quality (Class I), moderate quality (Class II or III) and low quality (Class IV) based on sample size, Egger's P value and between-study heterogeneity. In addition, subgroup analyses stratified by study baseline characteristics and leave-one-out sensitivity analyses were performed to explore the potential sources of heterogeneity and the stability of the results. RESULTS: Of 21 791 articles screened, 29 unique cohort studies comprising 150 252 patients were included in the data synthesis. Studies with high-quality evidence showed that older patients (≥60 years) (OR, 1.35; 95% CI, 1.03-1.77) were at higher risk for SEH. Studies with moderate-quality evidence suggested that patients with a BMI greater than or equal to 25 kg/m² (OR, 1.39; 95% CI, 1.10-1.76), hypertension (OR, 1.67; 95% CI, 1.28-2.17), and diabetes (OR, 1.25; 95% CI, 1.01-1.55) and those undergoing revision surgery (OR, 1.92; 95% CI, 1.15-3.25) and multilevel procedures (OR, 5.20; 95% CI, 2.89-9.37) were at higher risk for SEH. Meta-analysis revealed no association between tobacco use, operative time, anticoagulant use or American Society of Anesthesiologists (ASA) classification and SEH. CONCLUSIONS: Obvious risk factors for SEH include four patient-related risk factors, including older age, obesity, hypertension and diabetes, and two surgery-related risk factors, including revision surgery and multilevel procedures. These findings, however, must be interpreted with caution because most of these risk factors had small effect sizes. Nonetheless, they may help clinicians identify high-risk patients to improve prognosis.

The impact of diabetes on postoperative outcomes following spine surgery: A meta-analysis of 40 cohort studies with 2.9 million participants.

OBJECTIVE: Although diabetes mellitus (DM) is considered to be an important prognostic factor in spinal surgery, the relationship between these two factors remains unclear. The purpose of this study was to investigate whether diabetes is associated with an increased risk of postoperative complications in patients undergoing spinal surgery. METHODS: We systematically searched the PubMed, Embase, and Cochrane Library for relevant articles published on or before December 25, 2021. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random effects meta-analysis. The primary outcome was the risk of postoperative complications following spinal surgery, including postoperative infection and reoperation. Furthermore, we conducted subgroup analyses and leave-one-out sensitivity analyses to explore the main sources of heterogeneity and the stability of the results. RESULTS: A total of 40 cohort studies including 2,998,891 participants met the inclusion criteria. Meta-analysis showed that diabetes was significantly associated with postoperative infection (OR 2.21, 95% CI 1.70-2.88, p < 0.001) and reoperation (OR 1.35, 95% CI 1.12-1.64, p = 0.002). Furthermore, the results also found that diabetes was significantly associated with surgery-related death (OR 1.61, 95% CI 1.13-2.30, p = 0.008) and transfusions (OR 1.39, 95% CI 1.11-1.75, p = 0.005), whereas diabetes failed to account for nervous system complications (OR 1.12, 95% CI 0.82-1.52, p = 0.470) and embolism (OR 1.15, 95% CI 0.83-1.60, p = 0.386) for patients following spine surgery. These results were further confirmed by the trim-and-fill procedure and leave-one-out sensitivity analyses. CONCLUSIONS: Diabetes appears to be a risk factor for postoperative infection and reoperation for patients following spinal surgery. Special attention should be devoted to reducing the occurrence of postoperative complications in diabetic patients undergoing spinal surgery.